In a simple four step manufacturing process, the scrap rates for processes 1.2 3
ID: 2073891 • Letter: I
Question
In a simple four step manufacturing process, the scrap rates for processes 1.2 3, and 4 are 3%, 4%, 5%, and 5% respectively The dernard is 1000 good parts per shift (8-hr shift) Assume the scrap costs for processes 1, 2.3, and 4 are 5, $6, $7, and $10 respectively The standard times for processes 1.2, 3, and 4 are 5, 6, 8, and 10 min respectively 9. What is the required input to the first process to meet this demand? 10. What is the total scrap cost for this manufacturing system? 11. Find the number of machine fractions (do not round) needed per shift (8-hr shift) for each process. Assume 80% efficiency and 90% reliability for each process.Explanation / Answer
Initial input 100y
3% scrap in 1process,
Scrap 3y & good part 97y.
4% scrap in 2 process,
Scrap =97y (4/100)
=3.88y
Good parts =97y*(96/100)
=93.12y
5% scrap in 3process,
Scrap=93.12y*(5/100)
=4.656y
Good part=88.464y
5% scrap in 4 process,
Scrap=88.464y*(5/100)
=4.4232y
Good parts=84.0308y
Input require to meet demand=100*(1000/84.0308)
=1190
10. Total cost={(3*5)+(3.88*6)+(4.656*7)+(4.4232*10)}*(1190/100)
=(15+23.28+32.592+44.232)*11.9
=115.104*11.9
=$1370
11. number of machine =(.8*.9){(1190*5)/(60*8)}+(.8*.9){6*.97*1190)/(60*8)}+.......
=9+11+16+19
=55 nos machine